Can I add a library refence to existing Shared Object?

Thank you "Employed Russian", you gave me the information needed to search deeper. Solaris already ships with "elfedit", so if others wants to know, these are the instructions

# elfedit libfsimage.so.1.0.0 libfsimage.so.1.0.0-new> dyn:value DT_NEEDED index  tag                value   [0]  NEEDED            0x4f81              libpthread.so.1   [1]  NEEDED            0x4fac              libxml2.so.2   [2]  NEEDED            0x4fc2              libgcc_s.so.1> dyn:value -add -s DT_NEEDED libscf.so index  tag                value  [35]  NEEDED            0x500d              libscf.so> dyn:value DT_NEEDED index  tag                value   [0]  NEEDED            0x4f81              libpthread.so.1   [1]  NEEDED            0x4fac              libxml2.so.2   [2]  NEEDED            0x4fc2              libgcc_s.so.1  [35]  NEEDED            0x500d              libscf.so> :write> :quit# ldd libfsimage.so.1.0.0-new    libpthread.so.1 =>       /lib/libpthread.so.1    libxml2.so.2 =>  /lib/libxml2.so.2    libgcc_s.so.1 =>         /usr/sfw/lib/libgcc_s.so.1    libscf.so =>     /lib/libscf.so    libz.so.1 =>     /lib/libz.so.1    libm.so.2 =>     /lib/libm.so.2    libsocket.so.1 =>        /lib/libsocket.so.1    libnsl.so.1 =>   /lib/libnsl.so.1    libc.so.1 =>     /lib/libc.so.1    libuutil.so.1 =>         /lib/libuutil.so.1    libgen.so.1 =>   /lib/libgen.so.1    libnvpair.so.1 =>        /lib/libnvpair.so.1    libsmbios.so.1 =>        /usr/lib/libsmbios.so.1    libmp.so.2 =>    /lib/libmp.so.2    libmd.so.1 =>    /lib/libmd.so.1

Not easily.

Most UNIX systems (AIX is a notable exception) consider *.so a "final" link product, and it is not suitable as an input for any further link.

To add a new DT_NEEDED tag to the dynamic section of fsimage.so, you would need to rewrite its .dynamic section. Removing an entry from .dynamic is relatively easy -- you can just "slide" the other entries up, and replace the last entry with DT_NULL.

On the other hand, adding a new entry requires that you append a whole new .dynamic section to the file, and then update all pointers (offsets) within fsimage.so to point to the new section. This requires "deep" understanding of the ELF format.

There are existing tools to do this, e.g. rpath but I've had mixed success with it.

You can use PatchELF. Release 0.9 is out since 29 Feb 2016 and lets you:

• Change the dynamic loader ("ELF interpreter") of executables
• Change the RPATH of executables and libraries
• Shrink the RPATH of executables and libraries
• Remove declared dependencies on dynamic libraries (DT_NEEDEDentries)
• Add a declared dependency on a dynamic library (DT_NEEDED)
• Replace a declared dependency on a dynamic library with another one (DT_NEEDED)
• Change SONAME of a dynamic library

In your case:

$ patchelf --add-needed /usr/lib/libgen.so /usr/lib/python2.4/vendor-packages/fsimage.so